Commit 8aa60a6d authored Oct 31, 2018 by Marc Kleine-Budde Committed by Greg Kroah-Hartman Dec 01, 2018

can: dev: __can_get_echo_skb(): Don't crash the kernel if can_priv::echo_skb...


can: dev: __can_get_echo_skb(): Don't crash the kernel if can_priv::echo_skb is accessed out of bounds

commit e7a6994d043a1e31d5b17706a22ce33d2a3e4cdc upstream.

If the "struct can_priv::echo_skb" is accessed out of bounds would lead
to a kernel crash. Better print a sensible warning message instead and
try to recover.

Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 5adc1c54

drivers/net/can/dev.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -457,7 +457,11 @@ struct sk_buff __can_get_echo_skb(struct net_device dev, unsigned int idx, u8
		{
		struct can_priv *priv = netdev_priv(dev);

		BUG_ON(idx >= priv->echo_skb_max);
		if (idx >= priv->echo_skb_max) {
		netdev_err(dev, "%s: BUG! Trying to access can_priv::echo_skb out of bounds (%u/max %u)\n",
		__func__, idx, priv->echo_skb_max);
		return NULL;
		}

		if (priv->echo_skb[idx]) {
		/* Using "struct canfd_frame::len" for the frame